1. Technical Field
The present invention relates to a network control device and control method, and in particular to a network control device and control method in which packet filtering is implemented so as to receive only packets to be received by the self device, by determining whether or not a received packet is allowed to pass through based on header information at a predetermined position of the received packet, and additionally determining whether or not the received packet is allowed to pass through based on header information of a higher level protocol of the received packet that is not referred to in the preceding determination.
2. Related Art
Along with the recent development of network technology and widespread use of computers, it has been tried to realize more effective use of resources for example by network-connecting computers and a printer to share the printer or by network-connecting computers to have the computers share data.
A computer and a printer are typically provided with a power saving mode for implementing power saving control to reduce power consumption. In a network-connected printer, for example, the power saving control is implemented by stopping power supply to a part of the printer consuming large power (e.g., fixing unit) when no print data is received for a preset period of time.
According to this conventional power saving control method, a packet received through the network is once taken in the printer to determine whether the packet contains print data or not. If the packet contains print data, the power saving control is cancelled to supply power to the printer part the power supply to which has been stopped, and the printer shifts to the normal mode.